"Spaceman" is a song by the Killers. The song was released as the second single from the band's third studio album Day & Age on November 4, 2008, as a digital download on iTunes, and as 7" and promo CD in the US, Canada and the UK. From Wikipedia
The surprise duet underlines Dacus’s tour momentum behind her latest album with Flowers previewing two solo releases ahead of the next Killers record.